Existing transport refrigeration systems are used to cool containers, trailers, and other similar transport units. Modern containers may be efficiently stacked for shipment by ship or rail. When containers are shipped by a truck, a single container is placed on a container chassis. When cargo in the container includes perishable products (e.g., food product, flowers, etc.), the temperature of the container may be controlled to limit loss of the cargo during shipment.
Some existing transport containers include a generator set that supplies power to temperature-controlling components of the transport refrigeration system. These generator sets are typically attached directly to the container or container chassis, and include a prime mover to power a generator, as well as a fuel container to supply fuel to the generator sets.
Generator sets may operate at a single, relatively constant speed to produce a constant output frequency and one or more output voltages (e.g., 230/460 VAC, etc.). These generator sets may operate at the same single speed regardless of whether the load on the transport refrigeration system is relatively high or low, and therefore may not operate at the most fuel efficient condition. During extended periods of time without inspection by transportation workers, these generator sets may use up the fuel in the fuel container. The out-of-fuel condition can cause a loss of power to the transport refrigeration system, and may result in a loss of the perishable cargo. This is especially true when ambient temperature conditions are very hot or very cold.